vpopmail

The wonderful folks over at Inter7 developed vpopmail to handle the management of virtual domains using Qmail. Unfortunately vpopmail is limited to a measly 23 million virtual hosts,
of which each are limited to only 23 million users. So if you have
more than 529 trillion users you may need to look elsewhere.

Creating the vpopmail User and Group

As noted in vpopmail's INSTALL file, "[the]
FreeBSD folks have reserved 89 for the group and 89 for the user for
vpopmail." You will probably want to ensure vpopmail
is running as uid and gid 89.

I installed vpopmail into /var/lib/vpopmail, but
you can put it wherever you wish. Just remember that all email messages will be
stored in /var/lib/vpopmail, so choose a partition with plenty of
room.

Setting up MySQL Support

The first thing you need to do is set up vpopmail for MySQL.
This is done by doing some light code editing in a header file. Fire up your
favorite editor. Open up the file vmysql.h and change the
following lines to match the configuration you set up in the MySQL section of
this article:

There are a few things to note in the above configuration that you may want
to change to suit your needs.

I disable --enable-auth-logging because SquirrelMail logs in
and out every time a page is loaded, which can make logs grow quickly on active
mail servers.

The e option to --enable-logging enables logging
only of errors.

--enable-defaultquota The default quota can be computed by
using the equation (MB * 1024 * 1024) where MB is the number of megabytes you
would like your default quota to be.

You may need to specify the location of your MySQL include and library
directories with --enable-incdir and
--enable-libdir.

By disabling /etc/passwd with --enable-passwd=n,
only virtual users will have access to our mail server.

NFS users may wish to look at the --enable-file-locking and --enable-file-sync options. Because Qmail uses the alternative Maildir format to store messages, it works quite nicely with NFS.

After running the configure script, compile and install
vpopmail with the following commands:

bash$ make
bash$ make install-strip

Note: Debian has packages for vpopmail, however I could not
get them working properly with MySQL.

Creating Domains

Adding domains is extremely simple. Before you create a domain you will want
to read the man pages for vadddomain. There are options for mail
delivery, quotas, etc.

bash$ /path/to/vpopmail/bin/vadddomain example.com password

password is the password for postmaster@example.com, who will
be the administrator for that domain. After you have created the domain your
domain's user directories and .qmail files will exist in
/path/to/vpopmail/domains/example.com.

Adding Users

You can use either qmailadmin to create users or
vpopmail's vadduser.

bash$ /path/to/vpopmail/bin/vadduser username@example.com password

Courier IMAP

Courier IMAP is another piece of software by Inter7. It's a simple IMAP
server that was created specifically to work with Maildir. Read over the
INSTALL file before we get started to familiarize yourself with
the installation process.

Once you are done installing Courier IMAP, you need to edit a few
configuration options in its configuration file. Open
/usr/local/courier-imap/etc/imapd in your favorite editor and
change the following options.

editor's note: some of these options could use further
explanation

Change MAXDAEMONS to 40.

Raise MAXPERIP to 100. (Many users will
be using the web interface, which all come from a single IP.)

Change IMAP_EMPTYTRASH=Trash:7,Sent:30 to whatever you want.
This option tells Courier to clear out these folders every 7 and 30 days,
respectively. You can add extra folders there as well that you wish to have
the server empty periodically.

Change IMAPDSTART to YES.

After you have all of this up and running, you should be ready to fire up
your IMAP server. To start Courier IMAP at boot, copy
/usr/local/src/courier-imap-1.7.x/courier-imap.sysvinit to the
directory appropriate for your distro (many use /etc/init.d).

qmailadmin

qmailadmin is a CGI interface to vpopmail. It is totally optional, but will make administering your virtual domains, users, forwards, etc. much easier. Not only does it allow your postmaster to create and manage accounts, forwards, and aliases, but it allows users to log in and change passwords, set vacation messages, etc.

Note: qmailadmin requires EZMLM, DJB's mailing list manager, which you may not wish to install. You can skip this step.

Installing autoresponder

autoresponder is a prerequisite of qmailadmin and does basic auto responding. After you have extracted the source, change into the package's directory.

bash$ make
bash$ make man
bash$ make setup

Installing EZMLM

EZMLM is DJB's mailing list
software which works great with Qmail. EZMLM's main website has been down for
quite some time. I suggest you grab the source from DJB's EZMLM page. You will most likely wish to patch EZMLM with the famous IDX patch which adds a plethora of options. I found a working mirror where you can download ezmlm-idx-0.40.tar.gz. After you have extracted both the EZMLM source and the IDX patch, install EZMLM.

Installing qmailadmin

There are several options to look into if you plan to allow clients to
administer their own domains. --enable-maxpopusers and
--enable-maxmailinglists are just two of the options you may wish
to use. Be sure to check out ./configure --help for a complete
list of options.

bash$ make
bash$ make install-strip

After you have installed qmailadmin, you should be able to log
in to to http://example.com/cgi-bin/qmailadmin to administer your
domains.

Conclusion

Now that you have everything installed and have created your users, you
should be able to log in. Because vpopmail uses virtual hosts your
username will be username@example.com, which is important to
remember. Because of Qmail's flexibility and the power of
vpopmail's MySQL support you can easily create domains and hand
over the ability to manage accounts to your customers, which leaves plenty of
free time.

Now that your mail server is running the hard part is over, but it is not
yet complete. The second part of our series will cover installing Apache+PHP
and Squirrel Mail. We will also
customize Squirrel Mail with a few plugins that will make managing your web
mail system a lot easier. In the third and final part of our series, you will
see how easy it is to integrate both virus and spam protection into your new
mail server.

Joe Stump
is the Lead Architect for Digg where
he spends his time partitioning data, creating internal services, and
ensuring the code frameworks are in working order.